SYSTEMS NEUROSCIENCE ORIGINAL RESEARCH ARTICLE

movement. The large IFMs of the mesothorax function as a single contractile unit, generating the main propulsion during fl ight (Dutta et al., 2004). They are formed by the dorsal longitudinal muscles (DLMs) consisting of six fi bres, and three groups of dorsal– ventral muscles (DVM-I, DVM-II, and DVM-III) in each half of the thorax. DVM-I consists of three fi bres, DVM-II and DVM-III consist of two fi bres, each (Dutta et al., 2004). The largest muscle of the mesothorax is the tergal depressor of the trochanter (TDT), also called jump muscle enabling jump start of the fl y (Dutta et al., 2004). Unlike the IFMs, which generate the power for the wing beat, the DFMs are responsible for adjusting the orientation of the wings during fl ight. They are attached to the wing base in such a way that they can generate subtle torsions of the wings, which are responsible for controlling the direction of fl ight. Due to their fi ligree struc-ture and their complex spatial arrangement, 3D-reconstructions of the DFMs in the entire fl y are challenging, demonstrating the strengths of ultramicroscopy. The central nervous system (CNS) of Drosophila comprises the dorsally located brain enclosed by the head capsule, the thoracico-abdominal ganglion (ThAGl), and the cervical connective (CN), which connects the brain with the ThAGl (Hartenstein, 1993). In Drosophila the different thoracic ganglia are merged into two bonded masses of neural tissue, no ganglia exist in the abdomen (Miller, 1950). 3D-reconstructions of chemically cleared entire Drosophila were performed, using the ultramicroscopy setup described in Becker et al. (2008). The obtained reconstructions give detailed insight into the anatomy of the fl ight musculature, the nervous system, and the intestinal tract